Known timepieces include a power cell compartment generally closed by a cap which is latched onto the case by a bayonet mechanism and which is associated with a seal interposed between the cap and the case. Such seal, in the known type of arrangement, is constituted by a toroidal seal generally known under the designation of "O-ring" which does not give satisfaction for reasons of assembly.
Effectively, such type of seal during assembly has the tendency to be displaced relative to the cap and, being from then on incorrectly positioned relative to the case, does not in use assure the required sealing.
Thus, the present invention has as purpose to overcome this drawback by providing a timepiece in which the power cell compartment and the associated cap are provided with a gasket seal, the installation of which can be easily assured in a reliable and repetitive manner, while being capable of assuring perfect sealing under conditions of high pressure.